79.

And in [the interpretation of] this passage we must be very much on our guard against the error of those who judge from these same two trees that there are two original natures, the one of which belongs to God, but the other neither belongs to God nor springs from Him. And this error has both been already discussed in other books [of ours] ¹ very copiously, and if that is still too little, will be discussed again; but at present we have merely to show that the two trees before us do not help them. In the first place, because it is so clear that He is speaking of men, that whoever reads what goes before and what follows will wonder at their blindness. Secondly, they fix their attention on what is said, "A good tree cannot bring forth evil fruit, neither can a corrupt tree bring forth good fruit," and therefore think that neither can it happen that an evil soul should be changed into something better, nor a good one into something worse; as if it were said, A good tree cannot become evil, nor an evil tree good. But it is said, "A good tree cannot bring forth evil fruit, neither can a corrupt tree bring forth good fruit." For the tree is certainly the soul itself, i.e. the man himself, but the fruits are the works of the man; an evil man, therefore, cannot perform good works, nor a good man evil works. If an evil man, therefore, wishes to perform good works, let him first become good. So the Lord Himself says in another passage more plainly: "Either make the tree good, or make the tree bad." But if He were figuratively representing the two natures of such parties by these two trees, He would not say, "Make:" for who of the sons of men can make a nature? Then also in that passage, when He had made mention of these two trees, He added, "Ye hypocrites, how can ye, being evil, speak good things?" ² As long, therefore, as any one is evil, he cannot bring forth good fruits; for if he were to bring forth good fruits, he would no longer be evil. So it might most truly have been said, snow cannot be warm; for when it begins to be warm, we no longer call it snow, but water. It may therefore come about, that what was snow is no longer so; but it cannot happen that snow should be warm. So it may come about, that he who was evil is no longer evil; it cannot, however, happen that an evil man should do good. And although he is sometimes useful, this is not the man's own doing; but it is done through him, in virtue of the arrangements of divine providence: as, for instance, it is said of the Pharisees, "What they bid you, do; but what they do, do not consent to do." This very circumstance, that they spoke things that were good, and that the things which they spoke were usefully listened to and done, was not a matter belonging to them: for, says He, "they sit in Moses' seat." ³ It was, therefore, when engaged through divine providence in preaching the law of God, that they were able to be useful to their hearers, although they were not so to themselves. Respecting such it is said in another place by the prophet, "They have sown wheat, but shall reap thorns;" ⁴ because they teach what is good, and do what is evil. Those, therefore, who listened to them, and did what was said by them, did not gather grapes of thorns, but through the thorns gathered grapes of the vine: just as, were any one to thrust his hand through a hedge, or were at least to gather a grape from a vine which was entangled in a hedge, that would not be the fruit of the thorns, but of the vine.